Apparatus for coating webs, including adjustable doctor blade



March 1954 E. w. ERTNER APPARATUS FOR COATING WEBS, INCLUDING ADJUSTABLEDOCTOR BLADE Filed Aug. 25, 1951 FIG.4

INVENTOR. E. W. E R T N E R ATTORNEY Patented Mar. 16, 1954 APPARATUSFOR COATING WEBS,

IN CLUD- ING ADJUSTABLE DOCTOR BLADE Edward W. Ertner,

Chicago, Ill., assignor to Western Electric Company, Incorporated, NewYork, N. Y., a corporation of New York Application August 23, 1951,Serial No. 243,278 7 Claims. (01. 118-118) This invention relates toapparatus for coating webs, and more particularly to apparatus forapplying lacquer to webs.

In the manufacture of paper coated with lacquer or the like, on one facethereof, it is customary to apply lacquer to one face of the Web, thenspread the lacquer and take off excess lacquer with a doctor blade. Insuch coating operations it has been very diflicult in the past to applylacquer between precise margins, particularly if the web being coatedshifts somewhat during the coating operation.

An object of the invention is to provide new and improved apparatus forcoating webs.

A further object of the invention is to provide new and improvedapparatus for applying lacquer to webs.

Another object of the invention is to provide an adjustable doctor bladefor spreading coating liquid on a web Within precise limits.

An apparatus illustrating certain features of the invention may includemeans for applying a band of a predetermined width to one face of a web,and a doctor blade for scraping excess coating from the web andsmoothing the coating thereon. Means are provided for distributing theexcess lacquer on the doctor blade to increase the width of the band.

A complete understanding of the invention may b obtained from thefollowing detailed description of an apparatus formin a specificembodiment thereof, when read in conjunction with the appended drawings,in which Fig. 1 is a fragmentary, vertical view of a portion of anapparatus forming one embodiment of the invention;

Fig. 2 is a fragmentary, vertical section taken along line 22 of Fig. 1;

Fig. 3 is a fragmentary, perspective view of a doctor roll andsupplemental lacquer-feeding means forming a portion of the apparatus,and

Fig. 4. is a perspective view of the supplemental lacquer-feeding meansof the apparatus.

Referring now in detail receiving the lacquer from a fountain roll l3,which is continuously rotated and rotates the roll II. The web isadvanced from the roll ll under a guide roll and over a roll 16, whichis rotated at a peripheral speed opposite that of the web It! so thatexcess lacquer is wiped from the web 10 on the approach side of the rollI6. The roll 16 is rotated in a groove l1 formed in a holder 18 fastenedto a fixed support I9 by screws 20 projecting through slots 2|. The rollI6 is secured to arbors 25 mounted in bearings 26 carried by the support19 and is rotated by pulleys 21, 28 and 29 and a belt 30. An edge 3| ofthe groove I1 is sharp and scrapes excess lacquer from the roll it anddrops it back into a tank 32 holding lacquer and onto looped pins 34 and35, which project adjustably into grooves 36 and 3'! in the holder 18.The pins 34 and 35 are slidable in the grooves 36 and 31 and accumulateand spread lacquer received thereon fromthe roll 16 outwardly therealongto the looped portions thereof on the approach side of the roll 16, sothat the web l0 contacts th accumulated lacquer. By adjusting thepositions of the pins 34 and 35, the limits of the portion of the paperto which the lacquer is applied may be closely regulated, and the webmay be coated substantially from edge to edge without excess lacquer atthe edges thereof. The web 10 is advanced from the roll f5 partiallyaround a drying drum 40, which dries the lacquer, and is rolled into aroll 4|, which is rotated by rolls 42 and 43 to advance the paperthrough the apparatus described hereinabove.

Operation The web I 0 is advanced continuously by the rolls 42 and 43over the applicator roll II, the doctor roll 16 and the drying drum 4!].The applicator roll H, which is of a width less than that of the web l0,applies a band equal to the width thereof to the web If] between theedges of the web, the portions adjacent to which are left uncoated toprevent excess lacquer at the edges. As the coated portions of the webare advanced over the roll 16, the roll wipes excess lacquer therefromand smooths the portions left thereon, and most of the lacquer removedfrom the web I 0 by the roll l6 falls back into the tank 32 while theportion thereof scraped from the roll l6 at the U-shaped pins 34 and 35is accumulated and spread by the pins outwardly therealong. Uncoatedportions of the web contact the lacquer accumulated along the pins,which lacquer coats these portions of the web, thereby widening the areaof the portion of the web II) which is coated with the lacquer.

The above-described apparatus applies uniform coatings of lacquer inclosely controlled widths, and may be adjusted easily even while theapparatus is in operation by sliding the pins 34 and 35 in the grooves36 and 31.

It is to be understood that the above-described arrangements are simplyillustrative of the application of the principles of the invention.Numerous other arrangements may be readily devised by those skilled inthe art which will embody the principles of the invention and fallwithin the spirit and scope thereof.

What is claimed is:

l. A coating apparatus, which comprises means for applying a coatingliquid to a portion of one face of a web between the edges thereof, adoctor roll for removing a portion of the liquid applied to the face ofthe web, and means for spreading liquid removed by the doctor run alongthe doctor roll.

2. An apparatus for applying lacquer to web's, which comprises anapplicator roll having a predetermined length, means for advancing theweb of paper having a width greater than the length of the applicatorroll continuously over the applicator roll to apply lacquer to apredetermined portion of the web, a doctor roll contacting the entireface of the web having the lacquer applied thereto for removing excesslacquer from the portion of the web, and means for diverting excesslacquer removed by the doctor roll outwardly along the doctor roll toWiden the coated portion of the Web.

3. A coating apparatus, which comprises means for applying a coatingliquid to a portion of one face of a web intermediate the edges thereof,a doctor roll for removing a portion of the liquid applied to the faceof the web, and a guide for spreading liquid removed by the doctor rollalong the doctor roll toward the edge of the web and holding the liquidin contact with the web.

4. An apparatus for applying lacquer to webs, w ich comprises anapplicator roll having a predetermined length, means for advancing theweb of paper having a width greater than the length of the applicatorroll continuously over the applicator roll to apply lacquer to apredetermined portion of the web, a doctor roll contacting the entireface of the web having the lacquer applied thereto for removing excesslacquer from the portion of web, and means for scraping lacquer from thedoctor roll and diverting the lacquer outwardly along the doctor roll towiden the coated portion of the web.

5. A web-coating apparatus, which comprises means for applying lacquerto one face of a web leaving uncoated edge portions, a grooved rollscraper of a length substantially equal to the width of the coatedportion of the web, a doctor roll seated rotatably in the groove in theroll scraper, means for advancing the web continuously from thelacquer-applying means over the doctor roll in a predetermineddirection, means for rotating the roll at such a speed and in such adirection that there is a substantial algebraic ifference between theperipheral speed of the roll and the speed of the web, and pinsextending along the roll from the scraper for accumulating lacquerthereon to spread the lacquer along the roll to apply the lacquer to theuncoated edge portions of the web.

6. A web-coating apparatus, which comprises means for applying lacquerto one face of a web leaving uncoated edge portions, a grooved rollscraper of a length substantially equal to the width of the coatedportion of the web, a doctor roll seated rotatably in the groove in theroll scraper, means for advancing the web continuously from thelacquer-applying means over the doctor roll in a predetermineddirection, means for rotating the roll at such a speed and in such adirection that there is a substantial algebraic difference between theperipheral speed of the roll and the speed of the web, and pins mountedadjustably on the scraper and extending along the roll from the scraperin contact with the roll for accumulating lacquer thereon to spread thelacquer along the roll and apply the lacquer to the uncoated edgeportions of the web.

'2'. A web-coating apparatus, which comprises caving uncoated edgeportions, a grooved roll scraper of a length substantially equal to thewidth of the coated portion of the web having grooves on opposite sidesthereof, a doctor roll seated rotatably in the groove in the rollscraper, eans for advancing the web continuously from thelacquer-applying means over the doctor roll in a predetermineddirection, means for rotating the roll at such a speed and in such adirection that there is a substantial algebraic dirlerence between theperipheral speed of the roll and the speed of the web, and U-shaped pinsfitting slidaoly in said grooves in the roll scraper and extending alongthe roll from the scraper for accumulating lacquer thereon to spread thelacquer along the roll to apply it to the uncoated edge portions of theweb.

EDVJARD VJ. ERTNER.

References Cited in the file of this patent

